HBM EP 250 Instructions D'emploi page 9

EP 250
4.2 Strain gage installation
a) If strain gages with leads are used, that is without integral solder tabs, it is
recommended that solder terminals be attached to the strain gage. First
remove any oxide or other residues from the pads of the solder terminal
using a glass fiber brush. Then push the solder terminals between the
strain gage carrier foil and the lead and secure it with a narrow strip of the
enclosed Parmacel adhesive tape (See figs. 1 a and 1 b). Cut leads to suit
the distance between the end of the pads.
b) Put the strain gage, adhering side on top, onto a free spot of the object
slide. Use the spatula to apply a layer of adhesive that is as thin as possi-
ble onto the strain gage. Then place the strain gage on point of installa-
tion, align it and secure it in this position by sticking a piece of the enclo-
sed Permacel adhesive tape over it. The strip of adhesive tape should be
cut narrow enough not to cover the strain gage completely, so that excess
adhesive can escape on the two opposite sides during subsequent curing
under pressure, (fig. 2).
c) Now place a piece of the Teflon separating foil enclosed with the pack on
the point of installation, then a cushion of neoprene rubber (or silicone rub-
ber or several layers of soft blotting paper) and finally a flat metal plate.
Load this arrangement with a weight, or better still with a compression
spring, until a pressure of 10 N/cm
mon measurements in the field of stress analysis. For high-grade installa-
tions, or if hydrostatic pressure acts on the measuring point during measu-
rement, the pressure applied should be raised to 100 to 150 N/cm
Figure 1 a
Measuring grid
carrier cover foil
Measuring grid Measuring
carrier base foil grid
Figure 1 b
A1659-1.0 en/de/fr
2
Permacel tape
Leads
Solder terminal
is reached. This is sufficient for com-
Figure 2
Leave 1 mm edge free
from adhesive tape
9
2
.
Permacel
tape
HBM